Refrigerator construction with removable refrigerator unit



July 27, 1948. R. w. AYRES REFRIGERATOR CONSTRUCTION WITH REMOVABLE REFRIGERATOR UNIT 3 Sheets-Sheet 1 Filed July 14, 1943 fiiaaelt M V July 27, 1948.

Filed July 14, 1943 R. w. AYRES 2,445,988 REFRIGERATOR CONSTRUCTION WITH REMOVABLE REFRIGERATOR UNIT 3 Sheets-Sheet :2

July 27, 1948. R. w. AYRES 2,445,988

- REFRIGERATOR CONSTRUCTION WITH REMOVABLE REFRIGERATORIUNIT Filed July 14, 1943 3 Sheets-Sheet 3 Patented July 27, 1948 REFRI GERATOR CONSTRUCTION WITH REMOVABLE REFRIGERATOR UNIT Russell W. Ayres, Evansville, Ind., assignor, by mesne assignments, to Seeger Refrigerator Company, a corporation of Minnesota Application July 14, 1943, Serial No. 494,600

28 Claims. 1

My invention relates to mechanical refrigerator construction and more especially to improvements in household refrigerators of the type where the high side" unit of the refrigerating apparatus is located within the refrigerator cabinetp Among the principal objects of my invention is the provision of a more compact, efficient and economical arrangement of the refrigerating apparatus within the cabinet, and the freeing, for addition to the refrigerated food storage compartment, of a substantial volume of cabinet space formerly of necessity devoted to accommodation of the high side unit (that is, the compressor-motor-condenser unit). Or the newly freed space in the cabinet may be used to provide or enlarge a storage space, such as the vegetable bin, within the cabinet but without the refrigerated food storage compartment. Or it may be reflected in cabinets of reduced over-all sizes but undiminished in standard refrigerated storage volume ratings.

In present day household electric refrigerators, the high side unit is usually either bottom mounted or top mounted. That is, while the evaporator is located within the insulated food storage compartment usually adjacent the top thereof, the high side of the system is mounted either in the bottom of the cabinet beneath the refrigerated food storage compartment or in the top of the cabinet above the food storage compartment. The latter arrangement makes for the more compact package type of refrigerating apparatus, because the high side unit and the low side or evaporator unit are close-coupled, the latter usually being suspended on the underside of a removable top wall section of the insulated food compartment, and the high side unit being mounted on the top side of the removable section and within a high side compartment of the cabinet above the food storage compartment. This makes the entire refrigerating apparatus readily removable as a unit for servicing or replacement without the necessity of connecting or disconnecting refrigerant tubing or otherwise opening the closed refrigerant system. But in both top mounted and bottom mounted units, substantial cabinet space is taken to accommodate the high side unit. This amounts to two or more cubic feet in the popular sizes of househioid refrigerators.

By my arrangement, the high side unit is mounted at the back of, and in the back wall of, the cabinet and behind the evaporator. In so doing, I take advantage of certain previously wasted spaces, with the result that the space usually devoted to the accommodation of the high side unit is made available for effective use in refrigerated food storage or otherwise as above mentioned. One of these usually wasted spaces is the space between the back of the evaporator and the back wall of the storage compartment, which is inaccessible for food storage. Another is the three or four inch depth of space behind the back wall of the cabinet which is usually occupied by an air flue or air passageway to per mit the passage of cooling air upwardly along the back wall of the cabinet and between the cabinet and the wall of the room against which it is set.

With this placement of my high side unit to occupy these otherwise wasted spaces and my design and arrangement of the parts of the high side system and re-arrangement of certain necessary insulation, I am enabled to reduce the refrigerating apparatus in its entirety to a much more compact package" unit than was possible even with the relatively compact top mounted refrigerating apparatus above described. Another advantage is that the apparatus, being back mounted," is much more easily removed by one serviceman, partly because it is more readily detached and partly because its removal is horizontal rather than upward so that all of the movement occurs at a height convenient for the Serviceman.

Another object of my invention is to dissipate into external air, and to control the dissipation of, the heat produced by the motor and compressor in such a manner as to avoid the necessity of bringing quantities of air over the motor and compressor, whereby the motor and compressor may be compactly disposed in a small space; yet the evaporator in the refrigerated storage space is still adequately protected from the heat of the motor and compressor despite their proximity thereto, both by maintaining the compressor and motor below excessive temperatures and by adequate insulation between them and the evaporator and refrigerated compartment.

A further object of my invention, quite apart from the ready removability of the apparatus as a unit, is the ready separation therefrom of those component parts-such as the motor-compressor and the evaporator-as are most liable to need repair.

Still further objects of my invention :are concerned with: improvements in a separate refrigtor-compressor: solutions of problems arising therefrom when an inert gas is used with the refrigerant in the separate system; vibration-insulation mounting of the motor-compressor in the unit; framing of the unit for mounting in the cabinet; sound insulation for the motor-compressor; and an improved heat interchange between the liquid feed line and the suction return line.

These and other objects and advantages of my invention are set forth in the following de-' scription and the accompanying drawings of a specific embodiment of my invention.

Referring to the drawings, of which there are three sheets:

Fig. l is a vertical sectional view, taken in a front-to-rear plane, through the upper part of a domestic type refrigerator embodying the features of my invention;

Fig. 2 is a perspective view of the refrigerating unit alone;

Fig. 3 is a rear elevational view of the refrigerating unit installed, some parts being broken away and in section to reveal structural details;

Fig. 4 is a horizontal sectional view taken substantially along line 44 of Fig. 3; and

Fig. 5 is an enlarged vertical sectional view taken substantially along line 5-5 of Fig. 4.

In a refrigerator embodying the features of my invention, the cabinet may be of any popular commercial or preferred design as to external 3 ments, storage bin space, special shelving construction, etc. The only space occupied by the refrigerating apparatus within the confines of the cabinet proper, is that required for the evaporator and a very little space taken up by the heat insulating base plug upon which the motorcompressor assembly and the evaporator are mounted as a package unit, and which projects inwardly through an installation opening in the rear wall of the cabinet into formerly unused space back of the evaporator. A substantial proportion of the refrigeratin apparatus aside from the evaporator is through this arrangement accommodated within the thickness of the insulated rear wall .of the cabinet and projects only slightly rearwardly from the cabinet into a relatively narrow flue space in which is located the condenser structure of the unit. There is no need for disconnecting tubing or removing parts of the refrigerating apparatus piecemeal during servicing,

because, by removing a. few screws. the entire unit can be shifted away at the rear of the cabinet.

Having more particular reference to the drawings, a refrigeratin unit I0 is shown in conjunction with a household refrigerator cabinet ll of more or less conventional box design comprising a top wall l2, a bottom wall (not shown), side walls I3, 9. rear wall I, and a front wall l5, which may be in the form of a hinged door havin a latch (not shown) controlled by a handle Hi.

All these cabinet walls, of course, are of insulated construction, and they define a refrigerated food storage compartment I'l within the cabinet. Various appurtenances, such as shelving, meat saver, racks, etc., have been omitted from the drawings as unnecessary to a full understanding of the invention, but their use, if and as desired, will be understood.

The refrigerating unit i0 is of such small, compact and relatively lightweight construction that it can easily be installed, removed and handled by one Serviceman alone. As shown, it is of the compression type and includes on the low pressure side an evaporator l8 of any preferred construction. On the high pressure side, the unit Ill includes a sealed motor-compressor assembly I3 located back of, and in alignment with, the evaporator, and a condenser structure generally identified by the numeral 20. All of the apparatus is mounted upon a base structure 2| of preferably rectanguiar form, which provides an insulated partition between the evaporator l8 and the motor-compressor assembly. The base 2! also serves as an insulating plug for an opening 22 in the rear wall H of th cabinet dimensioned to permit passage of the evaporator l8 therethrough during installation or removal of the refrigerating unit.

At its forward end, the evaporator I 8 is supported conveniently adjacent to the door l5 by readily detachable means, such as bolts 23 suspended from the inside or roof surface of the top wall I2 and which engage brackets 24, one of which is located at each side of the evaporator. At its rear end, the evaporator I8 is removably attached to the mounting base plug 2| by means such as screws 25 respectively engaging top sidewall brackets 21 and bottom brackets 28 (Figs. 1 and 4) carried by the evaporator. A slight spaced relationship is maintained between the end of the evaporator l8 and the adjacent wall of the plug 2i so as to permit air circulation.

The distance between the rear end of the evaporator i8 and the plane of the inner face of the rear wall l4 may be, as shown, approximately equal to the thickness of the rear wall, in practice about three inches in an average size refrigerator. The front-to-rear or thickness dimension of the mounting base plug 2| is preferably sufiicient not only to fill the installation opening 22. but also substantially to fill the intervening distance to the evaporator which would otherwise probably be unused space. This makes it entirely practicable to mount the motor-compressor l9 to a substantial extent within the rear or outer side of the mounting base plug 2|, and yet preserve an insulated condition beween the motor-compressor and the interior of the refrigerator cabinet at least equal to the insulation afforded by the thickness of the rear wall I To this end the mountin base plug 2| is formed of much the same material as the rear wall I, and to a certain extent provides what may be considered as a removable portion of the rear wall inwardly offset to provide a recess 29 for accommodating the motor-compressor l9. Thus,- the plug 2i may be constructed as a sheet metal shell comprising an inner face member 30, which may be substantially cup"or pan shaped and telescoped over the inner margin of a rectangular tubular body member 3 I, to which it is secured removably by means such as screws 32 threaded into reinforcing bars 33 extending in a front-torear direction at the inside of the corners of the body member 3|. The reinforcing bars 33 at the top of the structure may have inner right angular end flanges 34 tapped to receive the evaporator bracket screws 25.

An outer closure plate 35 On the base plug is embossed with a substantially concave area 36 at the rear center of the plug extending inwardly to a maximum depth of not much more than half the thickness of the plug, to provide the recess 29. This closure plate is removably secured in place on the plug by means such as screws 31 threaded into appropriately bored and tapped right angular flanges 38 formed on the rear ends of the reinforcing bars 33 (Fig. 4), The interior of the shell thus formed is filled with heat insulating material 39 which may be the same as that used in the other wall structure of the cabinet ll. As seen in Figs. 1, 4 and 5, the effective thickness 01' this insulation within the plug is at all points practically equal to the thickness of insulation in the rear wall l1 and at many points even thicker.

The rear closure plate 35 is preferably of substantially greater horizonta1 and vertical dimensions than the installation opening 22, so as to overlap the surrounding rear face of the cabinet. The overlapping portions of the plate are then removably secured to the cabinet by screws 40 for holding the entire refrigerating unit III in place assisted, of course, by the bolted attachment of the evaporator Hi to the roof of the cabinet.

In order to reduce heat leakage between the secured margins of the plate 35 and the opposing cabinet wall surfaces to a minimum and prevent rattling, an airtight resilient seal is provided by a rubber or like gasket 4|, which is seated within an inwardly openin gasket channel 42 formed continuously around the margin of the plate and bears against the opposing cabinet wall surfaces.

A lamp 43 for illuminating the storage chamber I! may be carried by a lamp socket 44 mounted on the lower telescoping margin of the inner face member 30 of the plug shell, the adjacent wall of the tubular body member 3| being cut out as at 45 to accommodate the socket. The supporting area of the shell margin immediately surrounding the socket 44 is preferably upwardly oflset, as indicated at 41, in order to bring the outer. end of the socket 44 entirely within the lower face plane of the plug shell so as to clear the upper edge of the rear wall I4 at the installation opening when the plug- 2| is inserted or removed through the opening, The lam socket 44 may be connected into an electrical circuit controlled in any preferred manner by opening and closing of the door l5 of the cabinet.

A floating suspension for the motor-compressor l9 within the recess 29 is attained by the use of similar upper and lower coaxial coiled compression springs 48 and 49, respectively. The upper spring 48 is seated upon an apertured sheet metal bracket 50 secured to the adjacent upper outer surface of the recess embossment 36, At its upper end. the spring 48 supports a centrally depressed cap 5|, which is removably secured by means of of a screw 52 to the upper end of an axial boss 53 projecting upwardly from the motor-compressor casing through the bracket 50 into the spring 48. The lower suspension spring 49 is seated upon a bracket 54 and bears against a cupped thrust plate 55 held in centered position by an axial boss 51 extending downirom the motor-compressor casing. The suspension springs 43 and 49 hold the motor-compressor l9 out of direct engagement with any adjacent part of the plug structure and effectually absorb operating vibrations.

In the preferred arrangement, the axis of the motor-compressor I9 is located in or close to the major outer vertical plane of the closure plate 35, thereby affording a reasonably balanced distribution of weight in the refrigerating unit as a whole, since it places the dead weight of the motor compressor as far rearwardly as practicable and in that portion of the apparatus where it is more easily handled in the installation or removal of the apparatus. By this arrangement, also, a minimum of strain is imposed upon th closure plate 35 during handling of the refrigerating unit and also after installation since the weight is imposed in the direction of maximum strength of the plate. As a result of this relationship, about half of the motor-compressor assembly l3, or possibly a little more than half, is received freely within the recess 29 and the remainder projects rearwardly beyond the rear plane of the refrigerator cabinet, Such rearward projection however is not objectionable and to at least a certain extent is desirable since it places the motorcompressor 19 in the path of upmoving cooling air. Moreover, it permits the inwardly extending portion of the motor-compressor assembl to occupy space which actually goes not much deeper than the thickness of the rear wall H where, as in a typical example, the motor-compressor assembly is of an over-all diameter of six to seven inches, andthe rear wall I4 is approximately three inches thick.

A certain amount of operating noise may be emitted from the motor-compressor assembly while running, but such noise is effectively absorbed by enclosing the outwardly projecting portion of the motor-compressor with a spaced, embossed cover-plate 58,- substantially the counterpart of the rear plate embossment 36, and coating the inner surface of the cover-plate and. the outer surface of the embossment 36 with a layer of sound-absorbing anddeadening materail 59. This may comprise an asphalt base material that can be sprayed on to an effective coating of about one-sixteenth of an inch thickness. Such material has the advantage that th unit can be leak-tested by submerging it in water without affecting the sound-deadening qualities of the material.

Rattling of the cover-plate is prevented by inserting a sound deadening gasket 60 of resilient material such as rubber between an attachment flange 6| on the cover-plate and a gasket groove 62 offset within the plate 35 about the mouth of the recess embossment 36. For convenience in removal, the cover-plate 58 is formed in two portions. the major portion covering the upper part of the motor-compressor assembly and extending well down therealong and into overlapping relation to the upper edge of a lower cover-plate portion 63, from which it is separated by a sound deadening gasket 64, Screws 65 secure both portions of the cover-plate 58 in place removably.

Evaporated refrigerant is withdrawn from the evaporator l8 through a suction line 61, which enters the interior of the plug 2| through the inner face 30 adjacent the top of the evaporator. Thence the line 61 passes into the recess 23. through moisture sealing fixture 68 secured about an exit aperture 69 in the recess embossment 36 adjacent the motor-compressor assembly 13. After passing through a check-valve I0 the refrigerant gas enters the bottom of the motorcompressor assembly through an inlet duct portion H of the suction line.

Following compression, the refrigerant leaves the compressor through a high pressure duct 12 leading off from the top of the motor-compressor casing and passing out of the recess. 29 through an oifset passageway 12a in one side margin of the coverplate 58.

At its outer end the high pressure duct 12 communicates with an elongated finned-tube refrigerant condenser I3 which forms one part ofthecondenser structure 20. The condenser I3 is of relatively flattened shape and is supported immediately below the lower closure plate portion 63, horizontally lengthwise and upwardly and outwardly tilted transversely, by vertically extending rearwardly projecting parallel end plates I4.

14 and extend above the uppermost condenser fins and are removably secured by means of respective screws or bolts 11 to the lower ends of parallel vertical flue side plates I8 and I9, respectively. The latter extend to a short distance above the cover-plate 58 and are of a width only slightly greater than the maximum extent of the outward bulge of the cover-plate. At their rear edges the plates 18 and I9 are removably secured by screws or bolts 80 to respective pairs of vertically spaced angle brackets 8| on the outer face of the rear plate 35.

A vertically slidable protective closure and buffer plate 82 is received at its vertical edges within inwardly projecting right angular retaining flanges 83 on the outer vertical edges of the side plates I8 and I9 and aligned similar flanges 83a on upper forward edge portions of the condenser end plates 14 and 15 in front of the upper tube sections of the condenser, At its lower corners the slidable plate 82 rests upon horizontal inturned stop flanges 84 formed on the condenser end plates below the vertical flanges 83a. The cover 58 and the upper fins of the condenser 13 hold the plate 82 in place against the retaining flanges. The lower end of the vertical flue thus formed is completely traversed by the slanting refrigerant condenser I3. Heated air rising from the condenser is confined to the flue stack and th updraft is substantially unimpeded by cold air that might otherwise work in from the sides and the rear to throttle the draft. As a result of this fine arrangement, 'upsweep of cool air over the refrigerant condenser I3 is accelerated and the efficiency of the condenser improved.

Since the cover-plate 58 bulges directly into i the condenser air flue, it is swept by the rising air column and cooled of heat acquired by radiation from. the motor-compressor l9. Being substantlally streamlined, the cover-plate 58 offers no objectionable resistance to flue updraft.

Liquid refrigerant is led from the condenser I3 through a riser 85 and a silica jell dehydrator 86 to a high-side flow controlling float valve reservoir'8I. As best seen in Figs. 1, 2 and 3, the valve reservoir 81 is located above the condenser 13 between the bulge of the cover-plate 58 and side plate ii! to which it is connected by a supporting strap 88 extending across an air opening 89 from which the reservoir casing may project slightly. Below and extending up beside the innermost side of the reservoir 81 is an L-shaped shield 80 to deflect heated air rising from the condenser I3. Some cool air will be drawn into the condenser flue through the opening 89 and sweep and cool the reservoir 81.

From the reservoir 81 the liquid refrigerant is conveyed through a relatively long, restricted high pressure feed conduit slback to the evaporator I8. The feed conduit 8| extends through the passage 12a into the motor-compressor chamber, and through the sealing fixture 68 into the insulated space within the mounting plug 2|. Therein the conduit 9| is entwined about the suction line 81, which in the present instance is of considerable length and formed with several return bent loops, into a flat vertical coil embedded within the insulation 39. In this manner there is a transfer of residual heat from the high pressure feed line to the suction line, which affords the double advantage of lowering the temperature of the liquid refrigerant and raising the temperature of the spent refrigerant within the suction line so as to gasify liquid refrigerant that may pass over into the suction line. In order to attain maximum heat transfer contact with-the suction line, the high pressure feed conduit BI is preferablyof small diameter but it need not necessarily be of capillary fineness. The winding of the high pressure conduit is in a direction counter-current to the flow within the suction line 81. In order to avoid overheating of the motorcompressor assembly I!) during operation within the sound-proofed chamber 28, a free circulation secondary-type of cooling system is employed including a coil 92 formed of a plurality of Wind'- ings (three full windings being shown) tightly encircling the mid-portion of the motor-compressor casing horizontally. The system is charged with a refrigerant such as methylene chloride, which upon becoming heated vaporizes and flows from the upper winding of the coil 92 through a horizontal lead-off 93, which extends from the motor-compressor chamber outwardly through the passage 12a, and then is directed upwardly to an elongated condenser 84. The latter is carried horizontally by the upper end portions of the flue side plates I8 and I9 above the bulge of the cover-plate 58 across the top of the condenser air flue. The condensed refrigerant passes down from the condenser 84 through a return duct and a liquid trap loop 86 which communicates with the lower winding of the cooling coil 92 to complete the refrigerant circuit. Entry of the return duct into the motorcompressor chamber is through an outwardly offset transverse passage groove 95a in the adjacent side margin of the cover plate 58 (Fig. 3).

Inasmuch as the compressor operates most efficiently when it is reasonably warm, in the neighborhood of 110 to 115 F., means is preferably provided in the motor-compressor cooling system for maintaining the refrigerant quiescent until the optimum operating temperature is attained, whereafter. as the temperature increases, there will be circulation of refrigerant proportionate to increases in temperature reaching circulation near the point where a heatresponsive motor shut-oil device forming part of a starting and overload relay unit 91 (Fig. 3) becomes eiiective to stop the motor. Hereinsuch means comprises a non-condensable gas such as air enclosed within the system. In the cool state of the system, this non-condensable gas displaces refrigerant in the condenser 84 and maintains a pressure within the condenser whichrestrains circulation of the refrigerant until the predetermined compressor temperature of to F, is reached, whereafter the refrigerant gas pressure forces the non-condensable gas out of the condenser progressively as the temperature rises and the gas pressure correspondingly increases and pushes the air over into a collecing chamber in the form of a tube 98, which in the present instance comprises a blind end length of tubing leading oil at an upwardly slanting angle from the upper end of the return duct 95. Since the gas volume 98 slants towards the return duct, any liquid refrigerant carried over into the volume may freely run back into the liquid refrigerant stream.

To insure condensation, and consequent removal, of any refrigerant which might find its way into the collecting chamber 98, the latter should be located in a cool environmentat least as cool as the air passing over the condenser 94. This may compactly be effected. by placing the tube 98, as shown, beneath the condenser 94; although it could be placed in the surrounding atmosphere outside of the flue 82.

Where the system is charged with about 90 cc. of methylene chloride, a proper amount of air will be enclosed with the refrigerant where about a 22" vacuum is drawn at the time of admitting the refrigerant. As a result of this arrangement, the running temperature of the compressor can very nicely be held up to to 35 F. warmer than the condensing temperature of the refrigerant condenser 13, without the use of any mechanical controls in the motor-compressor cooling system. Even though the air which sweeps the condenser 94 of the motor-compressor cooling system is relatively heated by the heat absorbed from the refrigerant condenser 13, such air will still be cool enough to be entirely effective on the condenser 94 due to the'substantially higher operating temperature of the motor-compressor cooling system.

From the foregoing it will be apparent that my invention affords many practical advantages over prior domestic refrigerators, chief among which are the additional food storage space now made available; the small and efficiently compact arrangement of the refrigerating unit and the convenient back-mounting thereof in the refrigerator cabinet so that assembly and service-removal thereof are simplified and expedited; the emcient natural draft air cooling of the refrigerant condenser, as distinguished from the usual fan circulation cooling; the novel sound-proofing and temperature control of the motor-compressor which is simpler and more efiicient than has been attained heretofore; and the relatively small number of simply constructed parts used in the construction of the unit all of which are particularly well adapted for low cost quantity production methods of manufacture, so that the unit can be made and sold at a low competitive price while nevertheless giving substantially improved results.

It may be noted that for service purposes, every principal component of my refrigerating unit is easily and quickly accessible and separable. Thus, the evaporator is readily detachable from the supportin plug, the front and rear closure plates of the plug can be readily opened for entry into the plug, the motor-compressor is quickly exposed for inspection by sliding out the rear flue plate and opening the upper part of the motorcompressor cover-plate, the motor-compressor may then be released and removed from its recess after removing the flue side 'plates and lifting away the condenser of the motor-compressor cooling system, and the main refrigerant condenser can be removed conveniently andspeedily by detaching the end plates from the supporting apron. All of the refrigerant lines, ofcourse,

have appropriate readily accessible unions to facilitate assembly.

While I have illustrated a. preferred embodiment of the invention, many modifications may be made without departing from the spirit of the invention, and I do not wish to be limited to the precise details of construction set forth, but desire to avail myseli' of all changes within the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. A refrigerator comprising a cabinet having a food storage compartment and having aninsulated rear wall provided with an opening, a removable cooling unit comprising an insulated plug adapted to be inserted in the opening in said rear wall, said plug carrying an evaporator withinforwardly in said compartment, and said plug projecting into said compartment behind said evaporator to utilize space behind said evaporator and to provide insulation thickness for the plug substantially equal to that of the rear wall.

2. In a refrigerator construction adapted to increase the available space in the food storage compartment, the, combination of a substantially rectangular insulated cabinet provided with an insulated front closure and insulated walls, the rear wall of said cabinet being provided with an aperture, an insulated plug adapted to be inserted in said aperture and carrying an evaporator, said evaporator being shorter than the depth of said compartment from front to back 'and said evaporator, when inserted, being located forwardly in said compartment to utilize the space defined by a forward projection from said aperture in said cabinet and said plug being provided with insulation of substantially the same insulating characteristics as the walls of said cabinet, said plug, when inserted, projecting forwardly into the food compartment behind said evaporator and having its outer wall recessed to receive a refrigerating mechanism, a refrigerating mechanism carried by said plug, said mechanism projecting rearwardly out of said cabinet by a minimum amount due to the utilization of the space behind the evaporator.

3. In a refrigerator construction adapted to increase the available space in the food storage compartment, the combination of a substantially rectangular insulated cabinet provided with an insulated front closure and insulated walls, the rear wall of said cabinet being provided with an aperand thereafter over the compressor unit.

' 4. In a refrigerator construction adapted to increase the available space in the food storage compartment, the combination of a substantially rectangular insulated cabinet provided with an insulated front closure and insulated walls, the rear wall of said cabinet being provided with an aperture, an insulated plug adapted to be inserted in said aperture and carrying an evaporator, said evaporator being shorter than the depth of said compartment from front, to back and said evaporator, when inserted, being cated forwardly in said compartment to utilize the space defined by a forward projection from said aperture in said cabinet and said plug being provided with insulation of substantially the same insulating characteristics as the walls of saidcabinet, said plug, when inserted projecting forwardly into the food compartment behind said evaporator and having its outer wall recessed to receive a refrigerating mechanism, a refrigerating mechanism carried by said plug, said mechanism projecting rearwardly out of said cabinet by a minimum amount due to the utilization of the space behind the evaporator, said mechanism including a motor compressor unit and a condenser, said condenser being located below said compressor unit whereby the air passes by convection over the condenser and thereafter over the compressor unit, said mechanism including lateral and rear walls forming a flue and having a float chamber, said float chamber projecting from one of said latter walls but being partially baffled from the air stream from said condenser.

5. In combination in a refrigerator, a cabinet providing a refrigerated chamber and having an insulated rear wall formed with an opening therethrough, an insulating closure plug structure for said opening removable therefrom from the rear of the cabinet, an evaporator attached to the forward side of said plug structure within the chamber and removable with the plug structure rearwardly through said opening, a motor-compressor assembly mounted upon said plug structure rearwardly of said evaporator, and partially projecting beyond the back face of said rear wall, supporting means on the outer side of said plug structure extending substantially below the opening and the motor-compressor. assembly adjacent the back face of said rear wall and detachably secured thereto, and a refrigerant condenser communicating with said motor-compressor assembly and said evaporator and mounted providing a refrigerated chamber and ha ing l insulated rear wall formed with an opening therethrough, an insulating closure plug structure for said opening removable therefrom from the rear of the cabinet, an evaporator attached to the forward side of said plug structure within the chamber and removable with the plug structure rearwardly through said opening, a motorcompressor assembly mounted upon said plug structure rearwardly of said evaporator, and partially projecting beyond the back face of said rear wall, supporting means on the outer side of said plug structure extending-substantially below theopening and the motor 'comprcssor assembly adjacent the backface ofg s aid rear wall and detachably secured thereto, and a refrigerant condenser communicating vittluiiid lrno t or compressor assembly and said evaporator 'and mounted upon said supporting means, below the projection of the motor-compressor assembly 'to be cooled by updraft of air, induced by condenser heat, along the rear .of the cabinet, the motor-compressor assembly being enclosed withina chamber includ ing an outer wall which bulges in streamlined fashion rearwardly out over the refrigerant condenser into the air sweeping up therefrom.

7. A removable refrigerator unit comprising an insulating plug having a metallic housing of substantially rectangular shape, said plug having one of its walls formed with a recess for housing substantially half of a motor-compressor unit, and the thickness of said plug being sufficient to provide a thickness of insulation commensurate with that of the cabinet between the recess and the inner wall of said plug, an evaporator carried by the inner wall of said plug and communicating vwith the suction side of said motor-compressor, .a condenser located below said motor-compressor and extending upwardly and outwardly to be, interposed across the path of convection air currents passing upwardly toward said motor-compressor, a flue defined by side walls and rear wall members extending about the upper part of the condenser and said motor-compressor and having side walls attached to said plug whereby air passing over the condenser passes upward about the motor-compressor housing and tends to cool thesame, and a float chamber member located in the line between said condenser and said evaporator, said fioat chamber being exposed to cooling air at the side of the flue and being provided with a baffle for battling from the float chamber the warmer air passing upwardly from said condenser.

8. In combination in a household refrigerator, a cabinet enclosing a food storage compartment and having an insulated rear wall formed with an opening therethrough, a closure plug for said opening comprising a sheet metal shell including inner and outer Walls and filled with heat insulating material substantially equivalent in insulating efficiency to the insulation within the rear wall of the cabinet, an evaporator mounted upon the inner wall of the closure plug and extending into the food storage compartment, a motorcompressor assemlbly having a suction line in communication with said evaporator and mounted upon the outer wall of the closure plug, a refrigerant condenser having high pressure communication with said motor-compressor assembly and said evaporator and also mounted upon the outer closure plug wall, said suction line beingformed in part as a flat vertical coil and embedded in the insulation within said plug, and a high pressure feed line for conducting refrigerant from the condenser to the evaporator also extending through the insulation filled space within the plug and being in heat transfer contact with said suction line.

9. A household refrigerator as set forth in claim 8 wherein the front and rear walls of the ail-@088 closure plug are in the form of removable plates and the plug includes a tubular body member pro-i viding the remaining wall structure with the opposite ends of which the plates are engageable to close the plug shell.

10. In combination in a package type refrigerating unit adapted to be mounted at and through the rear of a refrigerator cabinet, an evaporator, a motor-compressor assembly, a common mounting base for said evaporator and said motor-compressor assembly comprising an insulated structure adapted to provide, a closure plug for an installation opening in the, rear wall of the refrigerator cabinet, a condenser communicating with said motor-compressor assembly and said evaporator and also mounted on said base, an air flue for said condenser forming a protective enclosure rearwardly of the motor-compressor assembly, and a valve-controlled reservoir for refrigerant in the line of communication between the condenser and the evaporator, said reservoir being mounted partially enclosed within said flue and beingarranged to be cooled by air unheated by the condenser.

- 11. A package type refrigerating unit including a mounting base structure constructed and arranged to provide a rearwardly removable closure block for a rear wall opening in a refrigerator cabinet, an evaporator mounted on the front side of the base structure to be inserted into or removed from the refrigerator cabinet through said opening, a motor-compressor assembly mounted on the rear side of the base structure and having suction communication with the evaporator, a main refrigerant condenser having high pressure communication with said motor compressor assembly and said evaporator, a cooling system for said motor-compressor assembly comprising a free circulating closed circuit charged with an evaporable refrigerant and including a condenser, and means removaibly securing said condensers to the rear side of said base structure with said motor-compressor cooling system condenser above the main refrigerant condenser, said securing means being constructed and arranged for independent removal of either of the condensers.

12. Refrigerating apparatus constituting a unitary package and comprising an insulation plug adapted to be inserted into an opening through the insulated wall of a refrigerator, an evaporator carried by the plug inwardlythereof to lie within the insulated refrigerated compartment of the refrigerator, the rear face of the plug being recessed, a motor-compressor assembly carried by the plug and disposed largely in the recess to lie largely within the wall of the refrigerator, an air-cooled condenser disposed to lie along the outside of the wall, an enclosure for the motor-compressor assembly, the compressor, condenser and evaporator being in communication to constitute a primary refrigerant system, and a second refrigerant system, arranged and constructed for free circulation by convection comprising an evaporator in heat-absorbing relation to the motor-compressor assembly and within its enclosure, and 'a condenser external to the enclosure and disposed along the wall of the refrigerator.

13. Refrigerating apparatus constituting a unitary package and comprising an insulation plug adapted to be inserted into an opening through the insulated wall of a refrigerator, an evaporator carried by the plug inwardly thereof to lie within the insulated refrigerated compartment of the refrigerator, the rear face of the plug being recessed, a motor-compressor assembly carried-by the plug and disposed largelyin the reces to lie largely within the wall of the refrigerator, an air-cooled condenser disposed to lie along the outside of the wall, the compressor, condenser and evaporator being in communication to constitutela primary refrigerant system, and a second refrigerant system, arranged and constructed for circulation by convection comprising an evaporator in heat-absorbing relation to the motor-compressor assembly, and a condenser external to the recess and exposed to outside cooling air.

14. Refrigerating apparatus according to claim 13 wherein the first-mentioned condenser is disposed to lie along the refrigerator wall below the motor-compressor assembly and the last-mentioned condenser is disposed to lie along the wall of the refrigerator above the motor-compressor assembly and wherein a vertical flue extends between the two condensers to provide a stack receiving air passing over the first-mentioned condenser and to discharge it over the second mentioned condenser.

15. In a heat dissipator for the motor-compressor assembly of a refrigerating unit, a motor compressor assembly and a separate system arranged and'constructed for circulation by convection charged with a vaporizing refrigerant and an inert gas and having an evaporator in heat-absorbing relation to the motor-compressor assembly, an air-cooled condenser, and a deadend chamber communicating with the discharge end of the condenser to receive the inert gas while the system is active and arranged to drain to the evaporator any refrigerant condensed in the volume chamber.

16. A heat dissipator according to claim 15 wherein the condenser and the dead end chamber are so positioned and arranged that the temperature surrounding the dead end chamber is lower than the temperature surrounding the condenser.

17. A heat dissipator according to claim 15 wherein the condenser lies in the path of an upilowing air-stream from the motor compressor assembly and the dead end chamber is positioned beneath the condenser and externally subjected to the air-stream before the air-stream reaches the condenser.

18. Refrigerating apparatus constituting a unitary package, comprising aninsulation-filled box-like plug adapted to be inserted into an opening in the insulated wall of a refrigerator, an evaporator carried by, and disposed beyond the inner face of the plug, a recess formed in the back of the plug, a motor-compressor assembly resiliently mounted on the plug and disposed largely within the recess but in part outwardly from the plug, a closure cap closing the recess to house the outwardly protruding part of the motor-compressor assembly, the plug having a marginal plate adapted to lie along and be secured to the wall of the refrigerator adjoining the opening, laterally spaced vertical plates extending outwardly from the marginal plate, a condenser communicating with the compressor andthe evaporator supported by and between the vertical plates below the motor-compressor assembly, a separate refrigerating system arranged and constructed for circulation by convection charged with a vaporizing refrigerant and including an evaporator in heat-absorbing relation to the motor-compressor assembly, and a condenser also mounted by and between the vertical plates and disposed above the motorcompressor assembly, whereby air may flow upproviding-a refrigerated chamber and having an insulated rear wall formed with an opening therethrough, an insulating closure plug structure for said opening removable therefrom from the rear of the cabinet, an evaporator attached to the forward side of said plug structure within the chamber and removable with the plug structure rearwardly through said opening. a motorcompressor assembly mounted upon said plug structure rearwardly of said evaporator, and partially projecting beyond the back face of said rear wall, supporting means on the outer side of said plug structure extending substantially below the opening and the motor-compressor assembly adjacent the back face of said rear wall and detachably secured thereto, and a refrigerant condenser communicating with said motor-compressor assembly and said evaporator and mounted upon said supporting means, below the projection of the motor-compressor assembly, to be cooled by updraft of air, induced by condenser heat, along the rear of the cabinet, the motorcompressor assembly being cooled by a free-circulating closed-circuit cooling system including a condenser mounted on the closure plug structure above the first-mentioned condenser and within the current of air sweeping upwardly therefrom.

21. A refrigerating apparatus including as a package unit, a supporting base structure, an evaporator on one side of said base structure, means defining a closed chamber on the opposite side of said base structure, a motor-compressor assembly mounted within-said chamber and having suction communication with the evaporator, a main condenser mounted on said base structure exteriorly of said chamber and communicating with said motor-compressor and said evaporator, means for cooling said motor-compressor assembly comprising a secondary refrigerant system arranged for free circulation by convection including a refrigerant coil in heat transfer relation to said motor-compressor assembly within the chamber, a communicating condenser exteriorly of the chamber mounted upon said base structure, the secondary motor-compressor cooling system containing a non-condensable gas for maintaining a pressure within the condenser of such system up to a predetermined motor-compressor temperature, and a chamber in said system for receiving the non-condensable gas when the refrigerant pressure increases proportionate to temperature increases of the motor-compres- -sor above said predetermined temperature and overbalances the non-condensable gas pressure whereby to displace such gas from the condenser. 22. A refrigerating apparatus including as a package unit. a supporting base structure. an evaporator on one side of said base structure, means defining a closed chamber on the opposite side of said base structure, a motor-compressor assembly mounted within said chamber and having suction communication with the evaporator. a main condenser mounted on said base structure exteriorly of said chamber and communicating with said motor-compressor and said evaporator, means for cooling said motor-compressor assembly comprising a secondary refrigerant system arranged for free circulation by convection including a refrigerant coil in heat transfer relation to said motor-compressor assembly within the chamber, and a communicating condenser exteriorly of the chamber mounted upon said base structure, the secondary motor-compressor cooling system including a non-condensable gas for,

maintaining the system inactive below a predetermined motor-compressor temperature, said i system including a chamber for receiving the non-condens'able gas when displaced by increased refrigerant pressure after the motor-compressor temperature attains said predetermined or higher temperature, and said motor-compressor cooling system including a liquid refrigerant flowpromoting trap between the condenser and the heat transfer coil and at a substantially lower elevation than the coil;

23. A refrigerating apparatus including a a package unit, a supporting base structure, an evaporator on one side of said base structure, means defining a closed chamber on the opposite side of said base structure, a motor-compressor assembly mounted within said chamber and having suction communication with the evaporator, a main condenser mounted on said base structure exteriorly of said chamber and communicating with said motor-compressor and said evaporator, means for cooling said motor-compressor assembly comprising a secondary refrigerant system arranged for free circulation by convection including a refrigerant coil in heat transfer relation to said motor-compressor assembly within the chamber, a communicating condenser exteriorly' of the chamber mounted upon said base structure, the secondary motor-compressor cooling system condenser being operated at a higher temperature than that of the main condenser and being mounted above the main condenser, and an air flue directing the heated air moving upwardly from the main condenser to travel in heatabstracting relation to the higher temperature cooling system condenser.

24. A secondary cooling system for a motor--v compressor comprising a closed tubular conduit having a plurality of cooling coils wrapped about the housing of a motor-compressor in heat-conducting contact therewith, whereby a charge of refrigerant in said coils is vaporized. the upper most of said coils communicating with a section of finned condenser tubing located to be cooled by convection currents of air passing upward around the motor-compressor unit, the said sec- 17 convection currents of air passing over the condenser section.

25. A cooling system for cooling the motor compressor units of refrigerator systems, comprising cooling coils in heat conducting contact with a part of the motor compressor unit, the said cooling coils having their upper outlet connected to a condenser, whereby refrigerant, which is caused to boil in the cooling coils, passes upward into the condenser, the condenser having its outlet connected by a return conduit to the lower inlet of the cooling coils, whereby the refrigerant vapor is condensed in the condenser to liquid which flows down by gravity to the cooling coils so that the cooling cycle may be repeated, the said system being provided with a separate housing forming an air chamber communicating with the condenser and return conduit, but located substantially out of the course of circulation of the refrigerant.

26. In a closed cooling system for cooling heated devices to a predetermined temperature, the combination of a condenser, comprising a tube, said tube communicating at one end with a downwardly extending conduit leading to metal cooling conduits which are in heat conducting relation to the device to be cooled, said latter cooling conduits being in communication at their uppermost end with a vapor conduit leading to the inlet end of said condenser, said system being closed and charged with refrigerant, whereby the heated device causes the refrigerant to boil in the cooling conduits and to pass up .the vapor conduit to the condenser, where the vapors are cooled and condensed to liquid, which passes out of the outlet end of the condenser down the return conduit to the cooling conduits to repeat the cycle, the said system also including a chamber located substantially out of the course of circulation of refrigerant, but communicating with said course for receiving a predetermined amount of noncondensable gas, whereby the system will not cool said device below a predetermined temperature, the said noncondensable gas being a predetermined amount of air which is left in the system by reducing the initial vacuum only to a predetermined point before charging with refrigerant, the said system including an amount of refrigerant which is adapted to fill the cooling conduits thereof, the said chamber being formed by a dead end portion of the condenser tube backwardly bent and located below the condenser to be subjected to cooling air currents drawn upward by the condenser.

27. In a closed cooling system for cooling heated devices to a predetermined temperature, the combination of a condenser, comprising a tube, said tube communicating at one end with a downwardly extending conduit leading to metal cooling conduits which are in heat conducting relation to the device to be cooled. said latter cooling conduits being in communication at their uppermost end with a vapor conduit leading to the inlet end of said condenser, said system being closed and charged with refrigerant, whereby the heated device causes the refrigerant to boil in the cooling conduits and to pass up the vapor conduit to the condenser, where the vapors are cooled and condensed to liquid, which passes out of the outlet end of the condenser down the return conduit to the cooling conduits to repeat the cycle. the said system also including a chamber located substantially out of the course of circulation of refrigerant, but communicating with said course for receiving a predetermined amount of noncondensable gas, whereby the system will not cool said device below a predetermined temperature, the said noncondensable gas being a predetermined amount of air which is left in the system by reducing the initial vacuum only to a predetermined point before charging with refrigerant, the said system including an amount of refrigerant which is adapted to fill the cooling conduits thereof, the said chamber comprising a separate closed housing member which communicates with the outlet end of the condenser and is located addacent the stream of air passing the condenser.

28. In a cooling system for a device heated with an intermittent source or heat. the combination of an air condenser having an inlet and an outlet, the inlet connecting with an evaporator coil arranged in heat absorption relationship with the source of heat and the other end of said evaporator coil being connected with the opposite end of said condenser. said condenser draining downward at one end toward the lower coils of the evaporator and being provided with a separate chamber communicating with and draining into the evaporator and located to be cooled by the air passing over the condenser, the said system being charged with a predetermined amount of refrigerant and a predetermined amount of noncondensable gas, whereby the refrigerant is evaporated by the heat from the heat source and .passes up into the higher end of the condenser to be condensed to liquid and drained back from the lower end of the condenser to the evaporator coils until a predetermined lower temperature is reached when the expansion of the noncondensable gas prevents the further eflec-tive operation of the cooling system except at higher temperatures.

RUSSELL W. LAYRES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 142,467 Austria July 25, 1935 

